<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body {
            background-color: #cde;
        }

        .word {
            font-weight: 700;
            margin: 120px;
            height: 30px;
        }

        .word::after {
            content: '';
            animation: dot 2s infinite;
            font-size: 12px;
        }

        /* 关键知识点：动画不同阶段可更改伪元素的content内容 */
        @keyframes dot {

            /* 零和100收尾保持一致 */
            0% {
                content: ''
            }

            25% {
                content: '😎'
            }

            50% {
                content: '😎😎'
            }

            75% {
                content: '😎😎😎'
            }

            100% {
                content: ''
            }

        }
    </style>
</head>

<body>
    <div class="word">诸位客官请稍后</div>
</body>

</html>